A preview of the sticker was posted on Gazeta Polska's Twitter feed on Wednesday and it is due to be included in next week's edition.

US ambassador to Poland Georgette Mosbacher expressed concern.

"I am disappointed and concerned that some groups use stickers to promote hatred and intolerance. We respect freedom of speech, but we must stand together on the side of values such as diversity and tolerance," Ms Mosbacher tweeted.

In response, the newspaper's editor, Tomasz Sakiewicz, tweeted that "being an activist in the gay movement does not make anyone more tolerant".

"Poles love freedom and have known the word tolerance for centuries. That's why they supported the rise of the USA," he added.

Paweł Rabiej, the deputy mayor of Warsaw, said he would file a complaint about the stickers to the prosecutor's office.

"German fascists created Jew-free zones," he tweeted.

"As you can see this tradition finds worthy followers, this time in Poland," he said, adding that it was happening "under the umbrella" of the governing party and bishops.

Polish attitudes to homosexuality are evolving but gay marriage is still outlawed, unlike in many Western European countries.